I could lessen you could lessen she could lessen we could lessen you could lessen they could lessen
V-ing form
I could be lessening you could be lessening she could be lessening we could be lessening you could be lessening they could be lessening
Perfect
I could have lessened you could have lessened she could have lessened we could have lessened you could have lessened they could have lessened
V-ing perfect
I could have been lessening you could have been lessening she could have been lessening we could have been lessening you could have been lessening they could have been lessening
Negation
Simple form
I couldn't lessen you couldn't lessen she couldn't lessen we couldn't lessen you couldn't lessen they couldn't lessen
V-ing form
I couldn't be lessening you couldn't be lessening she couldn't be lessening we couldn't be lessening you couldn't be lessening they couldn't be lessening
Perfect
I couldn't have lessened you couldn't have lessened she couldn't have lessened we couldn't have lessened you couldn't have lessened they couldn't have lessened
V-ing perfect
I couldn't have been lessening you couldn't have been lessening she couldn't have been lessening we couldn't have been lessening you couldn't have been lessening they couldn't have been lessening
Interrogative form
Simple form
could I lessen? could you lessen? could she lessen? could we lessen? could you lessen? could they lessen?
V-ing form
could I be lessening? could you be lessening? could she be lessening? could we be lessening? could you be lessening? could they be lessening?
Perfect
could I have lessened? could you have lessened? could she have lessened? could we have lessened? could you have lessened? could they have lessened?
V-ing perfect
could I have been lessening? could you have been lessening? could she have been lessening? could we have been lessening? could you have been lessening? could they have been lessening?
Interro-negative form
Simple form
couldn't I lessen? couldn't you lessen? couldn't she lessen? couldn't we lessen? couldn't you lessen? couldn't they lessen?
V-ing form
couldn't I be lessening? couldn't you be lessening? couldn't she be lessening? couldn't we be lessening? couldn't you be lessening? couldn't they be lessening?
Perfect
couldn't I have lessened? couldn't you have lessened? couldn't she have lessened? couldn't we have lessened? couldn't you have lessened? couldn't they have lessened?
V-ing perfect
couldn't I have been lessening? couldn't you have been lessening? couldn't she have been lessening? couldn't we have been lessening? couldn't you have been lessening? couldn't they have been lessening?